Sliding clasp fastener stringers

ABSTRACT

A slide fastener stringer comprising a knitted tape and a series of coupling elements secured thereto by loops of the knitting yarns drawn between successive elements and interlinked with one another.

United States Patent 1 1 'June 3, [969 Great Britain 27,972/69 6 Austinet ai. 1451 Aug. 7, 1973 SLIDING CLASP FASTENER STRINGERS [52] U.S. Cl.66/86 6 I t 2 Ch h F ed I u 27 [51] Int. Cl. D04!) 23/00 [7 1 ms 33%;: gfgg fif' i 58 Field of Search 66/86, 85, s4, 83; Simpson Crowther, 137Lichtield "2/2651 Rd., Four Oaks; David Warren, 4S6 Walmiey Rd., all ofSutton Coldfieid; [561 David Howitt, 24 Livingstone Rd., UNITED STATESPATENTS Birchfields, Birmingham. all of 3,176,637 4/1965 MacFee 112/105England 22 d: M 27 1972 Primary Exqmirte r R0nald Feldbaum 1 uAttorney-John W. Malley, Akin T. Davis et a1. [211 App]. No.: 238,594

Related U.S. Application Data [57] ABSTRACT [63] Continuation-impart ofSer. NO. 52,189, July 6, 1970. A sllde fastener Winser comprisms aknitted p and a series of coupling elements secured thereto by loops[30] Fol-d8 Appncaflon pfl Data of the knitting yarns drawn betweensuccessive elements and interlinked with one another.

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SHEET 2 or 6 PATENTEB AUG 7 SHEET 5 [IF 6 SLIDING CLASP FASTENERSTRINGERS This application is a continuation-in-part of application Ser.No. 52,189 filed July 6, 1970.

BACKGROUND OF THE INVENTION This invention relates to sliding claspfastener stringers and to methods and machines for their manufacture.

A sliding clasp fastener comprises two stringers, each stringercomprising a series of coupling elements secured to a carrier tape. Itis now well-known to provide a series of interconnected couplingelements formed from a length of plastics filament which is either woundinto a coil shape, or is formed into a meander configuration which isfolded along its center line into U- shape. A fastener having acoil-shape element construction will be referred to hereinafter as "coilfastener construction," and one having U-shaped elements will bereferred to hereinafter as "meander fastener construction." Other formsof interconnected coupling elements have been proposed wherein theelements are produced by notching a tube of plastics material, or bymoulding a series of elements having interconnecting portions formedintegrally with the elements.

SUMMARY OF THE INVENTION According to the present invention, a method ofmaking a sliding clasp fastener stringer comprises warp-knitting acarrier tape and, during the knitting, locating a series ofinterconnected coupling elements at one face of the tape and adjacent alongitudinal edge of the tape, moving a knitting needle between adjacentcoupling elements of the series to engage at least one of the knittingyarns, moving said knitting needle to draw a first loop of said yarnbetween adjacent coupling elements of the series, feeding the series ofelements and tape, and repeating the movements of said knitting needleso that a second loop of yarn drawn by said needle is interlinked withsaid first loop thereby to secure the series of coupling elements to theknitted tape.

Said knitting needle may move along a single rectilinear path betweencoupling elements of the series, or may be caused to move in the lappingsense of yarn guides of the machine when said needle is at the front ofthe machine so that said needle also reciprocates outside the series toform and interlink loops from two yarns.

The invention also includes a warp knitting machine for manufacturing asliding clasp fastener stringer, the machine having a knitting zone andcomprising a row of knitting needles for knitting a carrier tape of thestringer, a plurality of guide bars each carrying yarn guides, a tubularguide having a lower end disposed to guide a series of interconnectedcoupling elements to a predetermined position in the knitting zoneadjacent one end of the row of knitting needles, and means for moving aknitting needle through a plane containing the row of knitting needlesin a position beneath the tubular guide and through the path of movementof the series of elements at the knitting zone.

Additional means may be provided to move said knitting needle in thelapping sense of yarn guides of the machine when said needle is at thefront of the machine so that said needle reciprocates through said planeat laterally spaced positions.

The invention also includes a fastener stringer when made by a method orwith a machine as defined above.

BRIEF DESCRIPTION OF THE DRAWINGS Two embodiments of the invention willnow be described by way of example only, with reference to theaccompanying drawings in which:

FIG. 1 is a diagrammatic isometric view of part of a warp-knittingmachine according to a first embodiment during the manufacture of asliding clasp fastener; and also shows one stage in the manufacture of astringer according to a second embodiment;

FIGS. 2-4 show successive stages in a knitting cycle of the firstembodiment;

FIG. 4a is an isometricview of part of a practical machine according tothe first embodiment;

FIG. 4b is a view similar to FIG. 4a of other parts of the machine;

FIG. 4c is an end view of part of the machine of FIGS. 4a and 4b,-

FIG. 5 shows another stage in the manufacture of a stringer according tothe second embodiment;

FIG. 6 is an isometric view of part of a practical machine according tothe second embodiment; and

FIGS. 7 and 8 are views similar to FIG. 6 of other parts of the machineof the second embodiment.

The first embodiment will be described initially. with regard to FIGS. 1to 4 which show diagrammatically the-movement of the parts of themachineat a knitting station. The embodiment will then be described in greaterdetail with regard to FIGS. 44, b and c.

DESCRIPTION OF THE PREFERRED EMBODIMENTS are omitted for clarity.

Yams l4 are'fed downwardly in known manner from a yarn let-off motionand through the guides 13 to be knitted into a carrier tape 15. Some ofthe yarns, for example 140, are fed from independent let-off motions topermit the drawoff of a longer length of yarn compared with theremaining yarns 14.

A tubular guide 16 is fixedly mounted in a bracket 17 secured to an endframe of the machine. The lower end of the tubular guide is located at apredetermined position adjacent one end of the row of needles 1!, i.e.,adjacent a longitudinal edge of the tape 15 at the knitting zone and theguide is inclined forwardly of the machine to permit swinging andlapping movements of the yarn guides. A series of coupling elements 18in the form of a coil of plastics filament is fed downwardly through thetubular guide by a ratchet operated toothed wheel 100.

A hooked needle in the form of a latch needle 19 is mounted in a slide20 which is mounted for sliding movement in a slideway 20a at the frontof the machine and perpendicularly to and through the general plane ofthe row of needles 11 so that the needle 19 is disposed to move along arectilinear path below the tubular guide and between adjacent couplingelements 18.

For a conventional size of slide fastener fitted to dresswear, forexample, the pitch of the series of coupling elements is greater thanthe pitch of the courses of the knitted tape. In the present embodiment,therefore, the needle 19 is arranged to reciprocate twice betweenadjacent elements, i.e. while two courses of the tape are knitted, andthen to remain idle at the front of the machine whilst a third course isknitted and whilst a coupling element 18 is fed past the needle.

Immediately below the needle 19 a sinker blade 21 is mounted forreciprocation along a path parallel with the trickplate l and in timedrelationship with the needle.

During one cycle of the needle 19, when the needles 11 are at theirlower most positions having just knitted one course of the tape 15, theneedle 19 moves from the front towards the rear of the machine andbetween two of the yarns 14 (FIG. 1). On its return movement, the hook22 of the needle 19 engages one of the yarns (14a) and draws a loop 23of this yarn between two coupling elements 18 (FIG. 2) and through aprevious loop 24. This previous loop 24 is cast off the needle 19 and,in so doing, closes the latch of the needle 19 (FIG. 3). The knittedtape is then fed one course and the sinker blade 21 is moved to aposition in front of the series of elements 18 and beneath the needle 19(FIG. 4) so that on the next rearward movement of the needle 19 the loop23 is retained on the needle and slides along the shank thereby openingthe latch of the needle. Thus on each reciprocation of the needle 19, aloop of yarn 14a is interlinked with a previous loop of the yarn.

As the tape 15 is progressively formed by the knitting of yarns l4, andthe series of elements 18 is fed in unison with the tape by means of thetoothed wheel (not shown) two loops of the yarn 14a are formed betweeneach pair of elements and a third loop extends over a coupling elementon the side thereof remote from the tape 15. Since the yarn 14a is alsoknitted into the tape 15, the series of elements is secured to the tape.

In modifications of the first embodiment and depending upon the pitch ofthe elements 18, the needle 19 may pass at various intervals betweeneach successive pair of elements.

The first embodiment will now be described in greater detail withrespect to FIGS. 4a, b and c with regard to a practical machine. In themachine according to FIGS. 4a, b and c, a plurality of needles 19 arelocated in needle holders 30 which are spaced apart along a needle bar31 extending along the front of the machine, the holders 30 beinglocated by screws 32 in holes 33 in the needle bar. Only one holder 30is shown in FIG. 4a for clarity. The needle bar 31 is mounted along itslength at intervals upon levers 34 which are pivotally mounted upon ashaft 35 secured to the machine frame. A motion of the needles alongsubstantially rectilinear but slightly arcuate paths between the tubularguide 16 and adjacent coupling elements 18 as describd with regard toFIGS. 1 to 4, is produced by pivotting of the levers 34 in a controlledmanner. This controlled movement is provided by a cam follower 36 on anarm 37 of each lever 34, the cam follower being in engagement with aperipheral cam surface 38 of a cam 39 which itself is secured to a shaft40 (FIG. 40) which is drivable in synchronism with the rest of themachinery. FIG. 4a also shows material holding blades 41 which aredisposed on an L-shaped bracket 42 extending along the machine at theback of the needles 1 l. The material holding blades are moved as innormal manner for knitting machinery by a lever 43 FIG. 40)

to which the bracket 42 is secured, the lever being pivotally mountedupon the shaft 35 and pivotally movable by an actuating rod 36 which ismoved in synchronism with the movement of the needles 11. The movementof the holding blades 41 is thus synchronized with that of the needles11 so that the blades 41 occupy the position shown in FIGS. 4a and 4cduring the movement of the needles 11 between them whereby knitted tapematerial is held down and is not forced upwards by the needlesthemselves. The levers 43 are moved in an anti-clockwise cirection asshown by arrow A in FIG. 4c and out of the path of the needles when theneedles 11 move downwardly after a knitting operation to enable the lastcourse of knitted material to pass beneath the blades 41 in preparationfor the next holding operation.

Sinker blades 44 are disposed for horizontal movement beneath each ofthe needles 19 and are secured to a drive bar 45 which is movablehorizontally along the rear side of the needle bar 31 by means of adrive rod 46 (see FIG. 4b) which is secured at one end to the bar 45 andis secured at the other end to a short bar 47 which is slidable within ahousing block 48 secured to part of the machine frame 49. The sinkerblades on the bar 45 are moved in a horizontal direction in the normalway for knitting machinery by being spring loaded (by springs not shown)towards the right as shown in FIGS. 44 and 4b so that a cam follower 50at the end of the short bar 47 engages a peripheral cam surface 51 of acam 52 secured to a drive shaft 53 which is rotatably mounted anddrivable in the machine frame.

In front of the sinker blades 44 are a plurality of needle guides 54 asshown in FIGS. 44. The needle guides are of conventional constructionand operate in the normal manner for knitting machinery.

Needles 13 are mounted upon tour guide bars 55 which extend horizontallyacross the machine and hold groups of needles 13 for knitting each ofthe tapes, one group for each tape. In FIG. one group of the needles isshown. The guide bars 55 are movable In horizontal manner as shown inFIG. 4b by a drive rod 56 which is connected at one end to a block 57mounted on the guide bar and is secured at the other end to s short rod58 movable axially in the housing bracket 59 mounted on the part 49 of amachine frame. Each guide bar 55 is urged in conventional manner inknitting machinery towards the right by spring loading so that a camfollower 60 on the end of short rod 58 engages the peripheral camsurface 61 of a cam 62. Movement of each guide bar 55 by the cam 62provides the lapping movement of the needles attached tothst guide barin the normal way for knitting machinery so as to perform knittingoperations in conjunction with the independent lapping movement of theother guide bars. At intervals each guide bar is mounted by a bracket 63to an arcuste arm 64 which is pivotally mounted for swinging movement ina vertical plane upon a horizontal shaft 65 which extends fromside-toside of the machine. Each bracket 63 is sldsble upon guide pins63a upon the arms 64 so as to allow for the lapping movement of theguide bars. Movement of the arm 64 in its vertical plane providessimultaneous swinging movement of the guide bars and thus of the yarnguides 13 in a conventional manner for knitting machinery to move theyarns 14 between positions at the front and rear of the knittingneedles. This movement is provided by a crank 66 and a connecting rod 67with one end of the crank being secured to the shaft 65.

The machine described with reference to FIGS. 40, b and c attach theelements to the tape during knitting in the same way as has beendescribed for the basic construction with reference to FIGS. 1 to 4. Theknitting operation for each tape is performed in a conventional mannerfor knitting by forward and rear movement of the yarn guides by movementof the crank 66 as to pivot the arms 64 upon the shaft 65 and also bylapping movement of the yarn guides caused by horizontal movement of theguide bars 55 controlled by the cam 62 as described above. With theneedles 11 at their lowermost position after knittin one course of eachtape, the needles 19 move from the front to the rear of the machine byoperation of the lever 34 upon the shaft 35 by the cam 39 and eachneedle then returns drawing one of the yarns 14a with it between two ofthe coupling elements as described with reference to FIGS. 1 to 4. Afterthe tape has been fed one course, the sinker blade 44 is moved to aposition beneath the needle 19 so as to retain a loop of yarn upon theneedle as the needle again moves rearwardly of the machine and betweenthe elements. Movement of the sinker blade for each tape is controlledby the rod 45 by means of the cam 52 as described above.

In a second embodiment (FIGS. 1 and 5), a warpknitting machine used formaking a sliding clasp fastener stringer is similar to that describedfor the first embodiment. However, for the second embodiment, theslideway 200 is pivotally mounted on a horizontal axis XX.' The latchneedle 19 reciprocates backwards and forwards through the plane of therow of knitting needles 11 alternately at two different laterally spacedpositions, one position lying between coupling elements 18 and oneposition lying outside the series of elements at the side thereof remotefrom coupling head portions 18a. This will be seen by a comparison ofFIGS. 1 and 2. In order to obtain reciprocation of the needle 19 at thetwo positions, the needle is caused to move in the lapping sense of yarnguides 13 about the axis XX laterally with respect to the series ofcoupling elements 18, in a horizontal plane as indicated by arrow A inFIG. 5, when the needle 19 is at the front of the machine. This movementis imparted to the needle 19 by a push rod 25 secured at one end to theslide and driven from a cam (not shown) rotatably driven by a gear trainfrom the main shaft of the machine. Moreover, the needle 19, when at thefront of the trickplate 10, is given an oscillating motion about itslongitudinal axis through 120 by means of a crank 26 and connecting rod27 actuated by an eccentric on a shaft of the gear train which drivesthe push rod 25.

Also for this second embodiment two yarns 14a, 14b each have independentlet-off motions to permit the required draw-off of the yarns.

In operation, a loop of the yarn 14a is drawn between coupling elements18 as described in the first embodiment. With the needle 19 at the frontof the trickplate 10, the push rod moves the slide 20 and the needle 19in a horizontal arcuate path thereby moving the needle 19 to a laterallyspaced position at the outside of the series of elements 18. In order toprevent the loop of yarn 14a slipping from the hook 22 during thishorizontal movement, the needle 19 is oscillated clockwise about itsaxis through 120 by the connecting rod 25. Reciprocation of the slide 20then moves the needle 19 to the position shown in FIG. 5 so that theneedle engages the yarn 14b and draws a loop of the yarn 14b through aprevious loop of the yarn 14a and thus interlinks the yarns 14a and 14btogether around the filament of the elements. The needle is oscillatedanticlockwise through 120 and swung to its position for reciprocatingbetween adjacent elements 18 as in FIG. 1. Progressive interlinking ofthe yarns 14a and 14b in the above mannerthus secures the series ofelements 18 to the tape 15 whilst the tape is being knitted.

A practical machine for performing the second embodiment is describedwith reference to FIGS. 6, 7 and 8, most parts of which operate in asimilar manner to those described in the first embodiment with referenceto FIGS. 4a, b and c and like parts bear like reference numerals. In thesecond embodiment as shown in FIGS. 6 and 7, the oscillating movementreferred to with regard to FIGS. 1 and 5 is in practice performed by arack and pinion construction in which a rack 68 is slidable in a recess69 of the needle bar 31 and is engageable with pinions 70 secured one toeach of the needles 19 in making each of the tapes. As shown in FIG. 8,the rack is movable horizontally to impart oscillating movement to theneedles by means of a solenoid or air cylinder 71 which rotates a gearwheel 72 about a shaft 73 on a fixed axis by means of an arm 74 whichpivots around the shaft during movement of the drive rod 75 of thesolenoid. Rotation of the gear 72 causes the rack 68 to move in onedirection or the other. In this construction, each needle 19 is causedto move in the lapping sense of the yarn guides by movement oftheiieedle bar 31 horizontally across the front of the machine. Thismovement is very slight and will still mean that the cam follower 36 ofeach lever 34 engages the moving surface of cam 39 and to allow for thismovement, it is preferable that the shaft 35 is axially slidably mountedin the machine to enable the shaft, the arms 34 and needle bar to moveas one assembly in the horizontal direction. Movement of the needle bar31 is effected by reference to FIG. 7 by means of a drive shaft 76 whichis secured at one end to the needle bar 31 and at its other end carriesa short shaft 77 slidable within a housing 78. A cam follower 79 on theend of the shaft 78 lies in engagement with a peripheral cam surface 80of a cam 81. The needle bar 31 is spring loaded towards the right asshown in FIGS. 6 and 7 so that the cam follower always engages the .camsurface 80.

In a modification of this second embodiment, the series of couplingelements is provided with an internal cord in which case the needle 19must be reciprocated outside the path of movement of the cord.

Moreover, the series of coupling elements may be of other suitable form,for example, of meander fastener construction.

The series of coupling elements of the above embodimerits andmodifications thereof may further have notches or depressions on thesurface remote from the carrier tapes in order to provide a more securelocation for the loops of yarn extending over the elements and toprevent the loops slipping sideways off the elements.

Whereas the above embodiments have been described in relation tomachines employing latch-type knitting needles 11 and 19, the inventionmay also be performed with machines having bearded-type or compound-typeneedles.

What is claimed is:

l. A warp-knitting machine for making a sliding clasp fastener stringer,the machine having a knitting zone and comprising a row of knittingneedles for knitting a carrier tape of the stringer from a plurality offilaments of yarn, a plurality of guide bars each carrying yarn guides,a tubular guide having a lower end disposed to guide a series ofinterconnected coupling elements to a predetermined position in theknitting zone adjacent one end of the row of knitting needles, a hooktype knitting needle which is secured to a rotatably mounted lever so asto be movable substantially perpendicularly through a plane containingthe row of carrier tape knitting needles and filaments of yarn by afirst cam follower which is connected to said lever and is urged intoengagement with a first moving cam surface, said hook type needlefurther being located beneath the tubular guide for movement through thepath of movement of the series of coupling elements at the knitting zoneand said lever being mounted for lateral movement with respect to saidplane by means of a second cam follower which is connected to said leverand is urged into engagement with a second moving cam surface such thatthe hook of said hook type needle grasps a filament of yarn during thepenetration of said needle through said plane and withdraws saidfilament on one side of said coupling elements and then overlaps saidcoupling elements with said yarn before again penetrating said plane andmeans are provided for oscillating said hook type needle about its axisduring movements of the needle through said plane at said laterallyspaced positions so as to retain said yarn on said hook during theoverlapping movement from a first to a second laterally spaced position.

2. The warp-knitting machine as recited in claim 1 wherein said meansfor oscillating said hook type needle about its axis comprises a pinionmounted coaxially about said hook type needle, said needle being mountedto said lever so as to be rotatable about its axis and a rack adapted toengage said pinion and a means for reciprocating said rack.

3. The warp-knitting machine as recited in claim 2 wherein the means forreciprocating said rack comprises an air cylinder having a drive rod towhich one end of an arm is pivotally mounted the other end of said armbeing fixed to the axis of a gear wheel which is, in turn, adapted toengage said rack.

4. The warp-knitting machine as recited in claim 1 further including atleast one more hook type needle which is mounted parallel to said firsthook type needle so as to perform equivalent motions with respect tosaid coupling element and carrier tape.

5. A method of making a sliding clasp fastener stringer compriseswarp-knitting a carrier tape with a plurality of knitting needles whichoperate in a first plane and, during the knitting, locating a series ofinterconnected coupling elements at one face of the tape and adjacent alongitudinal edge of the tape, moving a knitting needle in a directionsubstantially perpendicular to and into said plane and over one of saidplurality of knitting needles between adjacent coupling elements of theseries to engage at least one of the knitting yarns, moving saidknitting needle in a direction substantially perpendicular to and out ofsaid plane to draw a first loop of said yarn between adjacent couplingelements of the series, feeding the series of elements and tape, andrepeating the movements of said knitting needle so that a second loop ofyarn drawn by said needle is interlinked with said first loop thereby tosecure the series of coupling elements to the knitting tape.

6. A method according to claim 5 wherein said knitting needle is causedto move along a single rectilinear path between coupling elements of theseries.

7. A method according to claim 5 wherein said knitting needle is causedto move in the lapping sense of yarn guides of the machine when saidneedle is at the front of the machine so that said needle alsoreciprocates outside the series andforms and interlinks loops from twoyarns.

8. A warp-knitting machine for making a sliding clasp fastener stringer,the machine having a knitting zone and comprising a row of knittingneedles for knitting a carrier tape of the stringer, a plurality ofguide bars each carrying yarn guides, a tubular guide having a lower enddisposed to guide a series of interconnected coupling elements to apredetermined position in the knitting zone adjacent one end of the rowof knitting needles, and means for moving a knitting needle through aplane containing the row of knitting needles in a position beneath thetubular guide and through the path of movement of the series of elementsat the knitting zone.

9. A machine according to claim 8 wherein said knitting needle movesalong a single rectilinear path through the path of movement of theseries of elements.

10. A machine according to claim 8 wherein means are provided to movesaid knitting needle in the lapping sense of yarn guides of the machinewhen said knitting needle is at the front of the machine so that saidneedle reciprocates through said plane at laterally spaced positions.

11. A machine according to claim 10 wherein said knitting needle is alatch needle and means are provided for oscillating said needle aboutitslongitudinal axis between movements of the needle through said plane atthe laterally spaced positions.

a s a s a

1. A warp-knitting machine for making a sliding clasp fastener stringer,the machine having a knitting zone and comprising a row of knittingneedles for knitting a carrier tape of the stringer from a plurality offilaments of yarn, a plurality of guide bars each carrying yarn guides,a tubular guide having a lower end disposed to guide a series ofinterconnected coupling elements to a predetermined position in theknitting zone adjacent one end of the row of knitting needles, a hooktype knitting needle which is secured to a rotatably mounted lever so asto be movable substantially perpendicularly through a plane containingthe row of carrier tape knitting needles and filaments of yarn by afirst cam follower which is connected to said lever and is urged intoengagement with a first moving cam surface, said hook type needlefurther being located beneath the tubular guide for movement through thepath of movement of the series of coupling elements at the knitting zoneand said lever being mounted for lateral movement with respect to saidplane by means of a second cam follower which is connected to said leverand is urged into engagement with a second moving cam surface such thatthe hook of said hook type needle grasps a filament of yarn during thepenetration of said needle through said plane and withdraws saidfilament on one side of said coupling elements and then overlaps saidcoupling elements with said yarn before again penetrating said plane andmeans are provided for oscillating said hook type needle about its axisduring movements of the needle through said plane at said laterallyspaced positions so as to retain said yarn on said hook during theoverlapping movement from a first to a second laterally spaced position.2. The warp-knitting machine as recited in claim 1 wherein said meansfor oscillating said hook type needle about its axis comprises a pinionmounted coaxially about said hook type needle, said needle being mountedto said lever so as to be rotatable about its axis and a rack adapted toengage said pinion and a means for reciprocating said rack.
 3. Thewarp-knitting machine as recited in claim 2 wherein the means forreciprocating said rack comprises an air cylinder having a drive rod towhich one end of an arm is pivotally mounted the other enD of said armbeing fixed to the axis of a gear wheel which is, in turn, adapted toengage said rack.
 4. The warp-knitting machine as recited in claim 1further including at least one more hook type needle which is mountedparallel to said first hook type needle so as to perform equivalentmotions with respect to said coupling element and carrier tape.
 5. Amethod of making a sliding clasp fastener stringer compriseswarp-knitting a carrier tape with a plurality of knitting needles whichoperate in a first plane and, during the knitting, locating a series ofinterconnected coupling elements at one face of the tape and adjacent alongitudinal edge of the tape, moving a knitting needle in a directionsubstantially perpendicular to and into said plane and over one of saidplurality of knitting needles between adjacent coupling elements of theseries to engage at least one of the knitting yarns, moving saidknitting needle in a direction substantially perpendicular to and out ofsaid plane to draw a first loop of said yarn between adjacent couplingelements of the series, feeding the series of elements and tape, andrepeating the movements of said knitting needle so that a second loop ofyarn drawn by said needle is interlinked with said first loop thereby tosecure the series of coupling elements to the knitting tape.
 6. A methodaccording to claim 5 wherein said knitting needle is caused to movealong a single rectilinear path between coupling elements of the series.7. A method according to claim 5 wherein said knitting needle is causedto move in the lapping sense of yarn guides of the machine when saidneedle is at the front of the machine so that said needle alsoreciprocates outside the series and forms and interlinks loops from twoyarns.
 8. A warp-knitting machine for making a sliding clasp fastenerstringer, the machine having a knitting zone and comprising a row ofknitting needles for knitting a carrier tape of the stringer, aplurality of guide bars each carrying yarn guides, a tubular guidehaving a lower end disposed to guide a series of interconnected couplingelements to a predetermined position in the knitting zone adjacent oneend of the row of knitting needles, and means for moving a knittingneedle through a plane containing the row of knitting needles in aposition beneath the tubular guide and through the path of movement ofthe series of elements at the knitting zone.
 9. A machine according toclaim 8 wherein said knitting needle moves along a single rectilinearpath through the path of movement of the series of elements.
 10. Amachine according to claim 8 wherein means are provided to move saidknitting needle in the lapping sense of yarn guides of the machine whensaid knitting needle is at the front of the machine so that said needlereciprocates through said plane at laterally spaced positions.
 11. Amachine according to claim 10 wherein said knitting needle is a latchneedle and means are provided for oscillating said needle about itslongitudinal axis between movements of the needle through said plane atthe laterally spaced positions.